Add AppleALC patching guide

Mainly relevant for newer laptops however also useful for fixing broken layout IDs for certain hardware. This guide would be based off of [Emily Dinesh's original AppleHDA patching guide](https://osxlatitude.com/forums/topic/1946-complete-applehda-patching-guide/) with useful information for integrating into AppleALC. Will also need to set certain rules for PRs:

* Never patch an existing layout ID, instead create a new one for your hardware. This avoids breaking layout IDs for others
* Ensure to use a unique layout ID for your codec, note certain layout IDs are reserved
* layout IDs 11-99 can be used so long as not already in use.

Currently this guide will likely be within the [Post Install site](https://dortania.github.io/OpenCore-Post-Install/) however if expanded enough we may move it into a dedicated guide. This will mostly depend how in depth this guide goes.

Ref:

* https://osxlatitude.com/forums/topic/1946-complete-applehda-patching-guide/